1、 Reference numberISO/IEC 14492:2001/Amd.2:2003(E)ISO/IEC 2003Information technology Lossy/lossless coding of bi-level images AMENDMENT 2: Extension of adaptive templates for halftone coding Technologies de linformation Codage avec ou sans perte des images au trait AMENDEMENT 2: Extensions des modles
2、 adaptatifs pour le codage des demi-teintes Amendment 2:2004 toNational Standard of CanadaCAN/CSA-ISO/IEC 14492:04Amendment 2:2003 to International Standard ISO/IEC 14492:2001 has been adopted without modification(IDT) as Amendment 2:2004 to CAN/CSA-ISO/IEC 14492:04. This Amendment was reviewed by t
3、he CSATechnical Committee on Information Technology (TCIT) under the jurisdiction of the Strategic SteeringCommitte on Information Technology and deemed acceptable for use in Canada.December 2004ISO/IEC 14492:2001/Amd.2:2003(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordan
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8、Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org ii ISO/IEC 2003 All rights reservedISO/IEC 14492:2001/Amd.2:2003(E) ISO/IEC 2003 All rights reserved iiiForeword ISO (the International Organization for Standardization) and IEC (the International Electrot
9、echnical Commission) form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical
10、 activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information technology, ISO and IEC have established a joint technical
11、committee, ISO/IEC JTC 1. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of the joint technical committee is to prepare International Standards. Draft International Standards adopted by the joint technical committee are circula
12、ted to national bodies for voting. Publication as an International Standard requires approval by at least 75 % of the national bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO and IEC shall not be held re
13、sponsible for identifying any or all such patent rights. Amendment 2 to ISO/IEC 14492:2001 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 29, Coding of audio, picture, multimedia and hypermedia information, in collaboration with ITU-T. The identical
14、text is published as ITU-T Rec. T.88 (2000)/Amd.2(06/2003). ISO/IEC 14492:2001/Amd.2:2003 (E) ITU-T Rec. T.88 (2000)/Amd.2 (06/2003) 1 INTERNATIONAL STANDARD ITU-T RECOMMENDATION Information technology Lossy/lossless coding of bi-level images Amendment 2 Extension of adaptive templates for halftone
15、coding 1) Subclause 4.2 a) Eight symbols for additional adaptive template pixels (from A5to A12) are added after A4as follows (with the additions underlined): A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12Adaptive template pixels in the generic region decoding procedure b) A new symbol “EXTTEMPLA
16、TE“ is inserted after the symbol “EXRUNLENGTH“ as follows (with the additions underlined): EXRUNLENGTH The length of a run of identical export flag values EXTTEMPLATE A parameter indicating whether extended reference template is used in a generic region decoding procedure c) New 16 symbols “GBATXi“
17、and “GBATYi“ (i=5,.,12) are inserted after “GBATY4“ as follows (with the additions underlined): GBATY4The Y location of adaptive template pixel 4 in a generic region decoding procedure GBATX5 The X location of adaptive template pixel 5 in a generic region decoding procedure GBATY5 The Y location of
18、adaptive template pixel 5 in a generic region decoding procedure GBATX6 The X location of adaptive template pixel 6 in a generic region decoding procedure GBATY6 The Y location of adaptive template pixel 6 in a generic region decoding procedure GBATX7 The X location of adaptive template pixel 7 in a
19、 generic region decoding procedure GBATY7 The Y location of adaptive template pixel 7 in a generic region decoding procedure GBATX8 The X location of adaptive template pixel 8 in a generic region decoding procedure GBATY8 The Y location of adaptive template pixel 8 in a generic region decoding proce
20、dure GBATX9 The X location of adaptive template pixel 9 in a generic region decoding procedure GBATY9 The Y location of adaptive template pixel 9 in a generic region decoding procedure GBATX10 The X location of adaptive template pixel 10 in a generic region decoding procedure GBATY10 The Y location
21、of adaptive template pixel 10 in a generic region decoding procedure GBATX11 The X location of adaptive template pixel 11 in a generic region decoding procedure GBATY11 The Y location of adaptive template pixel 11 in a generic region decoding procedure GBATX12 The X location of adaptive template pix
22、el 12 in a generic region decoding procedure GBATY12 The Y location of adaptive template pixel 12 in a generic region decoding procedure ISO/IEC 14492:2001/Amd.2:2003 (E) 2 ITU-T Rec. T.88 (2000)/Amd.2 (06/2003) 2) Subclause 6.2.2 In Table 2, new symbols “EXTTEMPLATE“, “GBATXi“ and “GBATYi“ (i=5,.,1
23、2) are inserted, and the notes of the table are revised as follows (with the additions and revisions underlined): Table 2 Parameters for the generic region decoding procedure Name Type Size (bits) Signed? Description and restrictions (Leave untouched) TPGDON Integer 1 N Whether typical prediction is
24、 used. a)EXTTEMPLATE Integer 1 N Whether extended reference template is used. e) (Leave untouched) GBATY4Integer 8 Y The Y location of the adaptive template pixel A4. b)GBATX5 Integer 8 Y The X location of the adaptive template pixel A5. d)GBATY5 Integer 8 Y The Y location of the adaptive template p
25、ixel A5. d)GBATX6 Integer 8 Y The X location of the adaptive template pixel A6. d)GBATY6 Integer 8 Y The Y location of the adaptive template pixel A6. d)GBATX7 Integer 8 Y The X location of the adaptive template pixel A7. d)GBATY7 Integer 8 Y The Y location of the adaptive template pixel A7. d)GBATX
26、8 Integer 8 Y The X location of the adaptive template pixel A8. d)GBATY8 Integer 8 Y The Y location of the adaptive template pixel A8. d)GBATX9 Integer 8 Y The X location of the adaptive template pixel A9. d)GBATY9 Integer 8 Y The Y location of the adaptive template pixel A9. d)GBATX10 Integer 8 Y T
27、he X location of the adaptive template pixel A10. d)GBATY10 Integer 8 Y The Y location of the adaptive template pixel A10. d)GBATX11 Integer 8 Y The X location of the adaptive template pixel A11. d)GBATY11 Integer 8 Y The Y location of the adaptive template pixel A11. d)GBATX12 Integer 8 Y The X loc
28、ation of the adaptive template pixel A12. d)GBATY12 Integer 8 Y The Y location of the adaptive template pixel A12. d)a)Unused if MMR = 1 b)Unused if MMR = 1 or GBTEMPLATE 0 c)Unused if USESKIP = 0 or MMR = 1 d)Used only if MMR = 0 and GBTEMPLATE = 0 and EXTTEMPLATE = 1 e)Used only if MMR = 0 and GBT
29、EMPLATE = 0 3) Subclause 6.2.5.3 a) The identification number of Figure 3 is changed to “Figure 3(a)“, and its caption is revised (with the additions and revisions underlined): X A4 XXXA3 A2 XXX X XA1 XXXFigure 3(a) Template when GBTEMPLATE = 0 and EXTTEMPLATE = 0, showing the AT pixels at their nom
30、inal locations ISO/IEC 14492:2001/Amd.2:2003 (E) ITU-T Rec. T.88 (2000)/Amd.2 (06/2003) 3 b) New Figure 3(b) is inserted as follows: X A11 A4 A2 A5 A9 A12 A3 X X X A6 A10A8 A7 A1 Figure 3(b) Template when GBTEMPLATE = 0 and EXTTEMPLATE = 1, showing the AT pixels at their nominal locations c) The sec
31、ond paragraph in subclause 6.2.5.3 is revised as follows (with the additions and revisions underlined): Figure 3(a) shows the template which shall be used when GBTEMPLATE is 0 and EXTTEMPLATE is 0. Figure 3(b) shows the template which shall be used when GBTEMPLATE is 0 and EXTTEMPLATE is 1. Figure 4
32、 shows the template which shall be used when GBTEMPLATE is 1. Figure 5 shows the template which shall be used when GBTEMPLATE is 2. Figure 6 shows the template which shall be used when GBTEMPLATE is 3. In each of these figures, the pixel denoted by a circle corresponds to the pixel to be coded and i
33、s not part of the template. The pixels denoted by X correspond to ordinary pixels in the template. The pixels denoted A1-A12are special pixels in the template. They are denoted “adaptive“ or AT pixels. These pixels are special in that their locations are not fixed, but can be placed at different loc
34、ations. See 6.2.5.4 for a description of AT pixels. The legends A1-A12indicate the AT pixels 1 to 12. The pixels actual locations are specified as parameters to this decoding procedure; Figures 3-6 show the nominal locations of these AT pixels for each template. 4) Subclause 6.2.5.4 a) The second pa
35、ragraph is revised as follows (with the additions and revisions underlined): The pixels that are allowed to change are called AT pixels. Their nominal locations are indicated by A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, and A12 in Figures 3(a), 3(b), 4, 5 and 6. Note that some templates have few
36、er than sixteen AT pixels. In general, an AT pixel can be located anywhere in the field shown in Figure 7, not including the current pixel. Hence, there is the possibility to use an effective template size of 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, or 4 pixels by having the moved location of the AT p
37、ixel overlap a regular template pixel. The actual locations of the AT pixels for any invocation of this decoding procedure are specified as parameters to the decoding procedure. The location of the pixel A1is given by (GBATX1, GBATY1). If GBTEMPLATE is 0, then: the location of the pixel A2is given b
38、y (GBATX2, GBATY2); the location of the pixel A3is given by (GBATX3, GBATY3); and the location of the pixel A4is given by (GBATX4, GBATY4). Additionally, if GBTEMPLATE is 0 and EXTTEMPLATE is 1, then: the location of the pixel A5is given by (GBATX5, GBATY5); the location of the pixel A6is given by (
39、GBATX6, GBATY6); the location of the pixel A7is given by (GBATX7, GBATY7); the location of the pixel A8is given by (GBATX8, GBATY8); the location of the pixel A9is given by (GBATX9, GBATY9); the location of the pixel A10is given by (GBATX10, GBATY10); the location of the pixel A11is given by (GBATX1
40、1, GBATY11); the location of the pixel A12is given by (GBATX12, GBATY12). b) Note 2 is revised as follows (with the additions and revisions underlined): NOTE 2 The indices of the AT pixels in Figures 3(a) and 3(b) correspond to the expected goodness. If moving only one AT pixel from the nominal loca
41、tion shown in Figure 3(a), it is advisable to move A4. The next pixel to move is A 3 and so on. ISO/IEC 14492:2001/Amd.2:2003 (E) 4 ITU-T Rec. T.88 (2000)/Amd.2 (06/2003) c) Table 5 is revised as follows (with the additions and revisions underlined): Table 5 The nominal values of the AT pixel locati
42、ons GBTEMPLATE 0 0 1 2 3 EXTTEMPLATE 1 0 0 0 0 GBATX1GBATY12 0 3 1 3 1 2 1 2 1 GBATX2GBATY20 2 3 1 NA NA NA NA NA NA GBATX3GBATY32 1 2 2 NA NA NA NA NA NA GBATX4GBATY41 2 2 2 NA NA NA NA NA NA GBATX5 GBATY5 1 2 NA NA NA NA NA NA NA NA GBATX6 GBATY6 2 1 NA NA NA NA NA NA NA NA GBATX7 GBATY7 3 0 NA NA
43、 NA NA NA NA NA NA GBATX8 GBATY8 4 0 NA NA NA NA NA NA NA NA GBATX9 GBATY9 2 2 NA NA NA NA NA NA NA NA GBATX10 GBATY10 3 1 NA NA NA NA NA NA NA NA GBATX11 GBATY11 2 2 NA NA NA NA NA NA NA NA GBATX12 GBATY12 3 1 NA NA NA NA NA NA NA NA NOTE NA means that the parameter has no nominal value. 5) Subclau
44、se 6.2.5.7 The step d) ii) is changed as follows (with the additions and revisions underlined): d) If LTP = 0 then, from left to right, decode each pixel of the current row of GBREG. The procedure for each pixel is as follows: i) If USESKIP is 1 and the pixel in the bitmap SKIP at the location corre
45、sponding to the current pixel is 1, then set the current pixel to 0. ii) Otherwise: Place the template given by parameters GBTEMPLATE, GBATX1through GBATX12 and GBATY1through GBATY12 so that the current pixel is aligned with the location denoted by a circle in the figure describing the appearance of
46、 the template with identifier GBTEMPLATE. 6) Subclause 7.4.6.2 a) Figure 46 is replaced by the following figure: EXTTEMPLATE Reserved Must be 0 TPGDON GBTEMPLATE MMR 7 6 5 4 3 2 1 0 Figure 46 Generic region segment flags field structure 7) Subclause 7.4.6.2 The notations of Bit 4 are added for EXTTE
47、MPLATE, and reserved bits are changed to Bits 5-7 as follows (with the additions and revisions underlined): Bit 4 EXTTEMPLATE This field specifies whether extended reference template is used. Bits 5-7 Reserved; must be zero. ISO/IEC 14492:2001/Amd.2:2003 (E) ITU-T Rec. T.88 (2000)/Amd.2 (06/2003) 5
48、8) Subclause 7.4.6.3 a) The first paragraph is changed as follows (with the additions and revisions underlined): This field is only present if MMR is 0. If GBTEMPLATE is 0 and EXTTEMPLATE is 0, it is an eight-byte field, formatted as shown in Figure 47(a) and as described below. b) The identificatio
49、n number of Figure 47 is changed to Figure 47(a) as follows (with the revision underlined): GBATX1 GBATY1 GBATX2 GBATY2 GBATX3 GBATY3 GBATX4 GBATY4 Figure 47(a) Generic region AT flags field structure when GBTEMPLATE is 0 and EXTTEMPLATE is 0 c) New Figure 47(b) is inserted immediately after as follows: GBATX1GBATY1GBATX2GBATX12GBATY2GBATY12T.88Amd.2_F47(b)Figure 47(b) Generic region AT flags field structure when GBTEMPLATE is 0 and EXTTEMPLATE
